Prevalence and significance of an abnormal exercise ECG in asymptomatic males. Outcome of thallium myocardial scintigraphy.

During a 3-year period 2500 asymptomatic male aviators were screened routinely for coronary artery disease by maximal bicycle exercise testing. In 55 cases (2.1%) the exercise ECG was abnormal (40 subjects exhibited ST depression, 14 ventricular ectopic activity and in one subject both abnormalities were observed). Further non-invasive studies (Thallium scintigraphy, echocardiography and ambulatory ECG monitoring for arrhythmias) identified nine out of the 55 aviators (16%, 95% CL = 7-26%) with an abnormal exercise test as having cardiac disease. We conclude that standard exercise ECG by itself is a poor predictor of coronary artery disease in asymptomatic subjects because of too many false-positives when the pre-test likelihood of disease is low. Therefore, exercise electrocardiography cannot be recommended as the single routine screening test for coronary artery disease in such individuals.